Pivotal joint



R WBROWN Jy w47.

Filed Aug 21' 1942 Awomam Patented July 29, 1947 PIVOTAL JOINT Roy W. Brown, Akron, Ohio, assignor to The Firestone Tire d; Rubber Company, Akron, Ohio, a

corporation of Ohio Application August 21, 1942, Serial No. 455,677

7 Claims. (CL 287-85) This invention relates to pivotal Joints, and more especially it relates to pivotal joints of the insulating type that comprise resilient bushings provided with permanently lubricated surfaces.

The application is a continuation in Dart of my copending application for Letters Patent, Serial No. 347,724, iiled July 26, 1940, now matured into Patent No. 2,324,984, issued July 20, i943.

The chief objects of the invention are to provide an improved pivotal joint that may be inexpensively manufactured; that consists of relatively few parts; that will not require adjustment during its useful life; that Will have insulating properties; that will have a controllable amount of shock absorbing properties; to provide a pivotal joint of the ball and socket type that will enable relative movement of the connected parts in the three planes at right angles to each other and rotational movement; toA provide yieldingly resilient centering means for the ball which will prevent the shell or casing of the socket element from having metal to metal contact with the shank of the ball, to the end thatexcessive wear and noise are obviated; to provide a Joint of the character mentioned that will be substantially tight against dirt, water, and other foreign matter encountered in normal use; and to provide a pivotal Joint having a dynamic c @cient o! friction greater than the static coe cient, that is, one in which less force is required toV initiate movement of the Joint than is necessary to maintain such movement. Other objects will be manifest as the description proceeds.

Of the accompanying drawing:

or casingll may also be of various forms, alternative constructions being disclosed in detail hereinafter; The bearing member Ill has an integral stud Illa that may be attached to an eye member 13;. the latterconstituting one of the twov elements that are connected by the pivotal Joint. The bushing i2 is composed of resilient rubber, or composition having substantially similar physical properties, and is provided with a flexible fabric lining I4 that is impregnated with a suitable lubricant, The bushing I2 is molded and vulcanized to proper form, the lining I 4 being vulcanized to the inner face of the bushing. Said inner face of the bushing is complementa] to the contour of the bearing member Ill, the bushing being designed to cover substantially all of the spherical portion of said member, except the stud portion Illa thereof. The external shape of the bushing I2 is substantially complemental to the contour of the inner face of the housing II.

The casing or housing lI preferably is made of a sheet metal stamping that is formed by pressing operations into a loop of the shape shown in Fig. 2 and of the cross-sectional shape shown in Fig. 1. The ends of the stamping are brought together and welded to a member I5 which is shown as a solid rod, but which may be hollow tubing if desired, said rod constituting the element to which member I3 is connected by the pivotal joint. The inside diameter of the open- Fig. 1 is an axial sectional view oi one embodi- 35 ment of the invention;

Fig. 2 is a plan view thereof as seen in the direction of the axis thereof;

Fig. 3 is a diametric section through another embodiment of the invention;

Fig. 4 is a diametric section through another embodiment of the invention;

Fig. 5 is a diametric section through still another embodiment of the invention;

Fig. 6 is a diametric section through yet another embodiment of the invention; and

ing extending through the loop-casing II is smaller than the outside diameter of the ball I0 so as to prevent removal of the latter from the finished joint. The bushing I2 may be of such normal external size as'to beplaced under compressive stress by the casing I l around it.

In the embodiment of the invention shown in Fig. 3 the outer housing, designated I8, is a metal f stamping of U-shape cross section. The general Fig. 7 is a plan view of the outer shell or housl 4ing element of the structure shown in Fig. 6.

Referring now to Fig. 1 and Fig. 2 of the drawing, there is shown a pivotal joint comprising an inner bearing member I0 shown as a. ball or sphere, an outer housing il, and an intermediate bushing I2. The ball member I0 may take varlous forms so long as it retains a substantially spherical healing surface, and the outer housing construction is somewhat similar to that previously described, except that the relative shape and size of the outer housing and the ball element i! is such that the latter has a. "snap assembly fit within a bushing 20 that is disposed between the ball and housing.` The housing I8'is of loop formation, and its marginal portions are inwardly turned to provide flanges 2l, 2i, the housing as a whole being united with a member 23 constituting one of the elements connected by the .pivotal joint. The diameter of the ball is smaller than the inside diameter of the inturned flanges 2| by an amount that is a little less than the thicknessof the bushing 2|) at the region of the flanges. Therefore, when the ball is snap fitted into or out of the open end ofthe bushing,

3 the part of the latter around the shank Ha of the ball will be stretched and also compressed, between the inner edge of the flange and the ball, as the latter passes the ange. The bushing 20 is formed with a central circumferential rib or flange 20a that engages the inner or confronting lateral faces of the flanges 2i of the housing and is thereby held against displacement axially of the housing. VAThe bushing 20 is somewhat similar to that shown in Fig. 1 in that it is provided with a fabric lining 22 that is impregnated with a suitable lubricant. `lI'he `ball I9, on the side thereof opposite the shank or stem I9a, is flat- Vvtened, and the bushing opposite said flattened region is so shaped as to provide a void or welll tween the ball member 26 and the housing 28, is molded and vulcanized to the initial shape as indicated by the broken lines. The bushing is retained in the joint by means of a metal disc 38 that is permanently secured in the large end of the tapered housing 'by the peening over of the housing ange 34 onto the marginal portion of the disc. The disc 38 is formed with a cylindrical axial re-entrant 38a that engages the adjacent marginal portion of the bushing 31 in the assembled joint, the bushing thereby being deformed to the shape shown in full lines in the drawing, and vput under compressive stress,

. whereby relative movement between the bushing and housing is obviated.

Thearrangement is such that there is a void 39 within thestructure contiguous with the flat surface'of the ball member 26, in which void a supply.cfilu-bricant may be placed, during asis bent into a loop, as in the previously described embodiments,V and welded tol a rod 28a that is pivotally'connectedto the eye member 21 by means of the joint. The loop or housing 23 is axially tapered, and at its small end is formed with an inturned circumferential flange 29.

Mounted between the housing 28 and the ball 2S is a flexible, annular rubber bushing 3U having its inner face provided'with fabric lining 3| that is impregnated Vwith lubricating material. The bushing with lining 3l attached thereto, is molded and vulcanized to the desired shape. the peripheral surface of the bushing being shaped substantially complemental to the inner circumferential surface of the housing loop 2l, the lining 3i extending onto the end face of the bushing,.at the smaller end thereof, so as to abut the housing flange 29 in the assembled condition of the joint. The inner surface of the bushing 30 is shaped complemental to the ball element 26,*but has an axial extension 38a. at the larger end ythereof, the lining 3i extendinginto said extension. At its larger end the annular housing is close by a disc 33 Vthat is centrally and outwardly cupies in the finished joint, so that the rubber of the bushing isplaced under compressive stress by the application of the disc 30.' This increases the friction between the housing and the bushing. and assures thatthe latter will not move relatively of the housing during service. The disc' 33 also serves to exclude dirt and other foreign matter from the working parts of the joint.

The embodiment of the invention shown in Fig, 5 is similar to that shown in Fig. 4, the ball element 26 and 26a, theeye member 21, and the- `housing member 28 being identical with similarly designated elements previously described. The flexible rubber bushing 31, that is positioned besembly of the joint. to lubricate the fabric lining 40 of the bushing 31. It will be observed thatl the bushing and its lining does not embrace the Y ball 26 closely adjacent the fiat surface of the latter, but is slightly spaced therefrom so that lubricant in the void 39 will make contact with the marginal portion of the lining 40.

The embodiment Vof the invention shown in Fig. 6 comprises a ball element 42, a housing element 43, and a flexible rubber bushing elementV 44. Y.The ball element has a fiat side simllarto those previously described, and diametrically opposite the flat side is integrally formed wltha threaded stud or shank for attachment to one of a pair of elements (not shown) that are connected by the joint. The housing element 43 is composed of a half-round metal rod that is bent into the shape of a circular loop of larger inside diameter than the diameter of the ball element 42, the flat sides of the rod being brought into face-to-face relation to complete the loop, the latter being permanently retained in shape by having its ends welded to the end of a rod 46 that kconstitutes one of the elements pivotally connected by the joint.

- Molded and vulcanized Within and to the loop of the .housing element 43 is the bushing element 44, the same comprising an interiorly formed socket in which the ball 42 is receivable. Said socket is complementa! to the shape of the ball, except the flat side and the shank portion 45 thereof, the axis of the spherical portion of the socket lying in the central plane of the housing 43. Furthermore, the. dimensionsv of the socket are somewhat smaller than the ball so that when the latter is mounted in the socket, the rubber of the bushing is under compressive stress because of its confinement bythe housing member. The socket in the bushing has a single flared orifice that is somewhat smaller in diameter than the ball 42, so as to admit the ball to said socket with a snap" fit. Opposite the fiat side of the ball the socket is so shaped that the wall thereof stands in spaced relation to the ball and thus provides a void or recess 49 within the bushing. The socket in the bushing has a facing of flexible fabric 50 vulcanized thereto which facing extends onto the surface of the flared orifice 48, but is omitted from the surface of the void 49, said fabric being impregnated with a suitable viscous lubricant. A reserve supply of said lubricant is deposited in the recess 49 at the time the joint is assembled, which supply will come into contact ywith the fabric facing 50 whenever the 'ball is rocked in the socket, thus assuring permanent lubrication of said facing.

invention, the rubber bushing is a one-piece struc-l,

ture, as also is the iiexible fabric lining thereof,

and that bushing and lining are integrally bonded to each other by vulcanization. The arrangement is such as to achieve uniformity of operation, and to prevent escape of lubricant from the bushing lining.

Other modifications may be resorted to without departing from the spirit of the invention, or the scope thereof as defined by the appended claims.

I claim:

1. An insulating and pivotal joint comprising an inner spherical bearing member, a one-piece resilient rubber bushing enveloping said spherical member and having a fabric lining bonded thereto and in contact with said spherical member and an outer housing comprising a stamped metal part formed into a loop and tightly encompassing said bushing so as to exert compressive stress thereon. n

2. An insulating and pivotal joint comprising an inner spherical bearing member, a resilient one-piece rubber bushing enveloping said spherical member and having a one-piece fabric lining bonded thereto and in contact with said spherical member, and an outer housing comprising a stamped metal part formed compassing said bushing, said loop having inturned margins to prevent axial displacement of said spherical bearing member with relation to said outer housing and to impart compressive stress to said bushing.

3. An insulating and pivotal joint comprising an inner spherical bearing member, a\ onepiece bushing of resilient rubber composition enveloping said member and integrally formed with a flexible fabric lining in contact with said spherical member, and an outer housing comprising a stamped metal part formed into a loop encompassing said bushing, the smallest diameter of the loop being larger than the outside diameter of the spherical member, the bushing having an opening therein formed with a flared orifice of smaller diameter than the diameter of the spherical member to enable the latter to be inserted readily in the bushing by way of said opening with a "snap fit.

4. An ,insulating and pivotal joint comprising an inner substantially spherical member, a onepiece bushing of resilient material substantially enveloping said spherical member and formed with a lubricated fabric lining in contact with the spherical member, said bushing formed with an enclosed recess confronting the spherical member and adapted to receive a reserve supply of lubricant, said fabric lining extending to said recess s as to have contact with lubricant therein, and a housing encompassing said bushing.

5. An insulating and pivotal joint comprising an inner substantially spherical bearing member, a ring-shaped one-piece bushing of resilient material encircling said spherical member and having a lubricated fabric lining in contact with the spherical member, an outer housing comprising a metal part formed into a loop encompassing said bushing, said housing having an inturned flange on one end thereof overlying an end of said bushing, and a metal disc closing the other end of the housing, said disc engaging a portion of said bushin a loop and ening to put the latter under compressive stress, and closing a recess in the structure contiguous with the spherical member, in which recess a reserve supplyof lubricant may be located.

6. A combination as dened in claim 5 whereof the fabric lining of the bushing extends into the recess in the structure so as to havetcontact with the lubricant therein.

7. An insulating and pivotal joint comprisingy an inner substantially spherical member, a onepiece bushing of resilient material substantially enveloping said spherical member and formed With alubricated fabric lining in contact with the spherical member, and a housing encompassing said bushing, the assembled joint having closure means extending across one side of said bushing and forming an enclosed recess confronting the spherical member and adapted to receive a reserve supply of lubricant, said fabric lining extending to said recess so as to have contact with lubricant therein.

ROY W. BROWN.

.REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,828,891 Crawford et a1 oct. 27, 193s` 2,236,062 Katcher Mar. 25, 1941 2,283,440 Huilerd May 19, 1942 2,274,417 Katcher Feb, 24, 1942 1,868,818 Eksergian July 26, 1932 1,909,100 Geyer May 16, 1933 2,216,987 Rose Oct. 8, 1940 1,828,358 Chryst' Oct. 20, 1931 1,989,116 Strauss Jan. 29, 1935 1,923,414 Benjamin Aug. 22, 1933 2,350,398 Huiierd June 6, 1944 FOREIGN PATENTS Number Country Date 128,693 Austria June 10, 1932 

